1. Field of the Invention
This invention relates to an improvement in a method of winding up a sheet web coated on its one side with a pressure-sensitive adhesive on a core tube with the adhesive side being a surface side.
2. Description of Related Art
Such rollers that are produced by winding up a sheet coated on its one side with a pressure-sensitive adhesive on a core tube so that the adhesive side may be a surface side are widely used in daily life, for example, as a gum roller for catching dust or refuse in a carpet, etc. This kind of roller was hitherto produced as shown in FIGS. 4 and 5 by winding up the aforesaid sheet or a film F fed continuously through a touch roller 11 on a core tube C revolving in the same direction as a turret T. When changing the sheet web from a full wind roll R to a new core tube C1, the new core tube C1 was subjected preliminarily to adhesive treatment such as a hot melt adhesive (made of cloth or the like) or a pressure-sensitive adhesive double coated tape, the sheet was cut between the full wind roll R and the new core tube C1 with a cutting blade 12, and the leading end of the cut sheet (non-adhesive side) was wrapped on the new core tube C1 at its adhesive side, thereby being bonded.
With the sheet coated with a pressure-sensitive adhesive as mentioned above, however, its pressure-sensitive adhesive side was, upon winding, an outer side to the core tube and its back side was subjected to a mold releasing treatment. Because of that, even if the new core tube was preliminarily subjected to the adhesive treatment, only a poor adhesion to the new core tube was obtained, and hence an improvement was demanded.
In order to cope with the problem in the conventional method above, the present applicant has proposed a method of improving the adhesiveness of the cut end of the sheet without the necessity of treating a new core with a hot melt adhesive or pressure-sensitive adhesive double coated tape and of enhancing the workability in a continuous winding of the sheet.
In winding up a sheet web coated with the aforesaid adhesive, this method comprises, when changing the sheet from a full wind roll wound up from the sheet web continuously fed to a winding position in a predetermined length to a new core tube, cutting the sheet web between the full wind roll moved and the new core tube located at the winding position, and simultaneously pressing and attaching the adhesive end of the cut sheet, while being in the running direction of the sheet web, to the new core tube and thereafter revolving the new core tube in reverse to the running direction of the sheet web and winding the attached sheet web onto the new core tube with the adhesive side being a surface side (JP P2001-240279A).
However when carrying the proposed method into effect, there has been a difficulty in workability upon roll changing and from the viewpoint of more effective roll changing, a further improvement over the method has been found to be necessary.
The invention has therefore been made by further developing the proposed method, and it is an object of this invention to facilitate changing the sheet web from a full roll to a new core tube, to smooth the continuous winding operation and to enhance the working efficiency.
The invention for attaining the aforesaid object resides in a method of winding continuously a sheet web coated on its one side with a pressure-sensitive adhesive onto a core tube on a turret winder, with the adhesive side being a surface side, which method is characterized in that when changing the sheet web from a full wind roll obtained by winding up the sheet web fed continuously to a winding position in a predetermined length to a new core tube, the new core tube is revolved in a reverse direction to the rotational direction of the turret, the sheet web is cut between the full wind roll moved by the rotation of the turret and the new core tube located at the winding position and revolving in the reverse direction to the rotational direction of the turret, the cut end of the sheet web being in the running direction of the sheet web is pressed and attached, at its adhesive side, to the surface of the new core tube under revolution in the reverse direction and concurrently, the attached sheet is folded back by the revolution of the new core tube in the reverse direction, and the sheet web continuing from the folded back portion is wound onto the new core tube, with the adhesive side being a surface side.
According to the method of the invention as described above, while the pressure-sensitive adhesive coated sheet web being fed is in the running direction of the sheet web accompanied by the rotation of the turret, its adhesive side comes into contact with the surface of a new core tube under revolution in the reverse direction to the rotational direction of the turret and the sheet web is cut with a cutting blade. Simultaneously with cutting, the leading end of the cut sheet web is bonded to the new core tube by taking advantage of the adhesive side. At that time because the revolution direction of the new core tube is reverse to the running direction of the sheet web accompanied by the rotation of the turret, the sheet web is folded back as soon as it is partly bonded and the sheet web continuing from the folded back portion will be wound on the new core tube with the adhesive side being a surface side.